Closure operator



S. P. SMURR.

CLOSURE OPERATOR.

APPLICATION man Fee. 3. 1919.

1,416,0'7 l Patente May 16, 1922.

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l, llY U. i l @7mm/@22H1 S. P. SMURR.

CLOSURE OPERATOR.

APPLICATION FILED FEB. s, 19m.

Patented May 16,y 1922.

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`cLosuRE OPERATOR.

APPLICATION FlLED 113.3, [919.

L41 @m1, Patented May 16, 1922.

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Jmmnr 5 Y E my P. SMURR.

CLOSURE OPERATOR.

APPLICATION FILED FEB. 3, IQIQ.

1,416,07 1 Patented May 16, 1922.

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atrae seras raras euries@ SAMUEL I. SM'URR, OF CHICAGO, ILLINOIS, ASSIGNOR TO VARIETY MANUFACTURING COMPANY, OF CHICAGO, ILLINOIS, .A CORPORATION OF ILLINOIS.

CLOSURE OPERATOR.

Specification of Letters Patent. Paiggntd ,May 16, 1922' Application led February 3, 1919. Serial No. 274,654'.

. In rolling lire shutters, lifting doors, etc.,

it is necessary to provide means which shall substantially counterbalance the weight of such closures to the end that they can be opened and closed easily. In some closures, for instance rolling fire shutters, it'is necessary that the counterbalancing ell'ect be automatically variable to correspond with the variable weight of the depending part ofthe shutter', viz: smaller when the shutter is wound up a'nd larger when the shutter is unwound. To accomplish this Apurpose many kdevices have been developed in which a coiled tension spring is wound up as the shutter descends, thus increasing the counterbalancing force. There are certain inherent defects in this form of counterbalance, the chief of which are the cost-of such springs, as they have to be made of large, heavy steel wire or rods, and the unreliabilityof such springs, due particularly to the necessity for attaching the ends of the springs to operating parts in a manner to resist the tension to which the springs are subjected. This connection is frequently accomplished by bending the ends of the springs at an angle and clamping or hooking them. to an operative part, but 'such bending and clamping produces possibilities of weakness which frequently develop into broken springs with all their attendant and following expense of repairs and possibility of break down at a critical time.

By means of my invention I am enabled to retain the advantages of the coiled spring and to. eliminate the detrimental features balance which is not only reliable but is `also capable of being manufactured at relatively low cost.

These advantages are based on the fact that I provide means for making the expansive force of a coiled compression spring effective as a counterbalancing force, and in doing this it is not necessary to distort or attach the ends ofthe spring. So far as I am informed, I am the first to so employ or apply a coiled compression spring and in doing so I .provide mechanism to convert the rectilinear expansion of a coiled compression spring to produce relative rotation between two members for rolling and unrolling fire shutters, orl for winding up 'or unwinding cables for operating lift doors, etc. Upon a full understanding of my inlvention it will be seen that my invention is not limited in its', application to closures but that it can readily be made use of in other mechanisms whereln it is desirable to produce a limited relative rotation of two members.

The essence of my invention resides in the association -of two rotatable members, a coiled compression spring arranged. between them, the expansive power of' the spring made available to relatively rotate said members by a quick thread screw and nut thereon, the nut caused to travel on the screw by the pressure of the spring.

It will be understood, of course, that vari'-` ous details of construction are required to operatively relate these elements .and it` should be understood that they may be' related in many ways to produce desired results, that instead of the elements both rotating, either one may be held stationary and the other rotate, that the elements may be arranged as a shaft' within atube or drum, or 1n other relations, the essential fea-v ture being that a coiled compression spring is `used with means for converting the rectilinear movement of the spring as it expands into a rotary movement of one element or of the relative rotative movement of two elements.

vMy invention will be more readily underd stood by reference to said drawings, in which I have illustrated the application of my infeatures of construction disclosed in Figure,

vention to a Irollin fire shutter and toa horizontal foldingV oor; and

Figure 1 is a fragmentary elevational view, partly in section, of a rolling lire shutter made in accordance with my invention;

Figures 2 and 3 are detail vertical sections on the lines 2--2 and 3-3 respectively of Figure 1;

Figure 4 is an elevationallview of a horizontal foldin counterbalancing .device made in accordance with my invention;

Figure 5 isa-vertical section on 5 5 of Figure 4;

Figure 6 is a central longitudinal section of the counterbalance device shown in Figure 4; '4 .A Figure 7 is a vertical sectional View on the hne 7-7 of Figure 6;

Figure 8 is a detail vertical section on thev l1ne 8 8 of Figure 6;

Figures 9 and 10 are detailvertical seci` tional views similar to Fi ures 2 and 3 illustrating various forms o construction embodying the principles o fnmy invention;

Figure 11 is a yfragmentary isometric view of the shaft employed in connection4 with the forms shown in Figures 9 and 10; and Figure 12 is a front elevational ViewA of the drum of a rolling shutter showing the the line 9 in connection therewith.v v

In said drawings, 10 is one of the rotatable elements and in Figures 1 to 3 inclusive the other rotatable element 11 is a drum upon which a flexible metal window shutter 12 isadapted to be wound. One end of the curtainis secured to the periphery of the drum by screws 13 and 'as the drum revolves in one direction or the other the curtain or shutter 12 is raised or lowered as may be, the edges of the curtain being guided in suitable channel guides 14.

The drum 11 is mounted at vits ends on heads 15 and 16 and the shaft 10 is centrall mounted and rotatable in the heads. The head 15 is provided with a central projection 17 which .is rotatably mounted in a bracket 18 which is secured to and projects" from the wall of the building and the outer end of the projection 17 carries a gear 19 by means .of which the drum 11 may be rotated to windand unwind the curtain. I provide a pinion 20 meshin with the gear 19 and a chain wheel 21 rigi with the pinion and a hand chain 22 for rotating the gear 19.

At the opposite end ofthe drum the head 16v is rotatably mounted on the shaft 10 and the shaft in turn is mounted in a bearing provided in a bracket 23 which is secured tothe wall of the building and by which the end of the device is supported. The brackets 18 and 23 form end walls for a curtain casing 13 and the casing is comdoor in combination with a the drum rotate together.

close the ends of the drum and the drum thus serves as a closed chamber in which to hold lubricant.

My novel form of counterbalance comprises a relatively long pitch screw thread which I provide on the shaft, a nut which is adapted to be moved along the shaft by the rotation of the drum and a compression spring which is adapted to be controlled by the nut. The screw thread4 is preferably of av long pitch so that the expansive force of the spring will force the nut longitudinally of the the shaft and cause the relative rotation of the shaft and drum. In the form shown in Figure 1 the shaft 10 is vsquare within the drum and I heat 'the shaft and twist it to form the screw threads 25 thereon. I make the threads of substantially 45 large enough to allow the twisted shaft to slide through same and I provide thread enf gaging plu s 28, one for each thread, secured in ra ial `hOles 29 provided 1n the nut 26. I preferably make the holes 29 on the diagonal diameters of the nut, as this provides ln er holes than if they were made in the flat sldes of the nut. The inner end 30 of each plug is rounded to fit in the screw threadgroove inthe shaft. The plugs are held tightly in the holes 29 as by being driven into same. Y

To engage the nut 26 with the drum 11 I provide` a tube 31 of square section and of a size. to fit loosely on the nut 26 and within' which the nut can freely slide, and I secure one end of the tube 31 to a central square projection 32 on the inner end of the head 16 by the screws 33 so that the tube 31 and x I hold the opposite end 34 of the tube 31 centrally in relation to the shaft 10 by which I secure to the shaft 10. The head 35 is circular and while it can form a bearing for the square tube I prefer'to form the corners. of the tube inwardly at said end 34 so as to `assist in holding lubricant within the square tube for lubricating the screw end nut. The head 35 is Secured rigidly upon the shaft 10 as by the set screw 36 to rotate therewith. Between the head 35 which is a relatively fixed abutment and the nut 26i which is a relatively movable abuta head or collar 35 i rotation thereof. It is 'conceivable that I.

-sion spring ment, I interpose a simple coiled compres- 37. rIhe spring' surrounds the shaft 10 Within the square tube 31 and is adapted to be compressed when the drum is turned in a direction to unwind the curtain and to be permitted to expand when the drum is turned to wind `up the curtain, consequently the force of the spring increases as the curtain descends and'thus requires more force to counterbalance it and vice versau The square tube 31 -provides a plurality of 'longitudinal grooves on the drum in which the nut is engaged andthe twisting of the shaft forms spiral grooves on the shaft with which the nut engages, so that longitudinal movement of the nut betweenthese two members causes a relative might effect the relative rotation of these two elements by a single groove in each, that the spiral groove miglitbe in the drum and the straight groove on the shaft and that the essential features might be arranged in any other relation without departing` from the spirit of my invention. While, as'explained herei'nbefore, my balancing device can be arranged to permit either element to rotate, in the form shown in Figure 1 the drum rotates and I hold the shaft `l() against rotation. For this purpose I provide a ratchet holdingfdevice which ermits the rotation of the shaft 10 for adjusting the compression of the spring, to properly counterbalance the curtain. This device'consists of a head or disk 38 secured on one end of the shaft and provided with a number of radial holes 39 at its eriphery, in which theend of a bar can be p aced to turn the shaft 10, and

also adapted to receive a locking pin 40.

The locking pin is held in a bracket 41 secured to the end bracket 18 of the casing.

To hold the spring 37 central and free of the shaftI provide the nut with a central projection 42 and the fixed abutment 35 with a similar central projection 43 which projections enter within the ends ofthe spring. It will now be clear that the counterbal-' ance of vmy invention is a compactl strong device, that I do not have to bend nor distort nor even fasten the ends of the spring, that the springis in its best possible condition for'constant use, being merely compressed and extended and that it does not have to resist any other distorting strain. This form of -sprlng is the cheapest formgto manufacture' and is the least liable to break A4in. use. s It will also be clear that I am enabled to minimize the working friction of my device and'keep it constantly lubricated as the square tube and the drum form a casing which is tightly closed, in which to hold the lubricant. There is no end friction to absisted by the head 35 and the nut, both of ing force of the spring to the curtain as it descends to properly counterbalance it at' all times. There are other formsfof movable closures in which the weight to-be counterbalanced is substantially constant. This would be exactly true of a door or closure which was arranged to slide vertically to open and close, and I provide means for compensating the variable force of the compression sprlng to provide a' counterbalancing force which is substantially constant, or I could go even further than this and produce such variations in counterbalancing force as to properly counterbalance a closure which requires a variable lifting force to counterbalance it which force does not change in consonance with the changing force of the spring.

In said Figures 4 to 8 I have illustrated a horizontal folding door of the kind used to close the doors of warehouses, etc. Doors of this character usually consist of an upper section 50 and a lower section 51, the two sect-ions hinged together at their horizontal meeting edges b thehinges 52. The upper section is hinge to the wall of the building l'iy hinges 53 above the door opening 54. he lower edge 55 of the lower section .is guided vertically so that when the door is hinges to the position shown in dotted lines in Figure 5. Vertical j guide grooves 56 are `provided one at each edge of the door opening, and the lower part of the .door is provided with guide shoes 57 adapted to slide in the grooves. The shoes are pivoted to the edges of the door by horizontal pivot pins 58 mounted in brackets 59. For lifting a door of this character I provide a horizontal shaft -60 rotatably mounted in brackets 61 secured to the wall of thebuilding above the door.` On one end of the shaft I secure a gear 62 and I provide aI pin-f ion 63 meshin -with the gear and a chain wheel 64 and c ain 65 for rotating the shaft 60 by hand. -For counterbalancing the weight of the door, which is substantially constant, I provide la tubular housing v6,4 surrounding the middle portion of the shaft 60; in -the form shown this tubular housing is formed of a square tube. I close the ends of the tube by heads 65 and 66 providing central holes in the heads through which the shaft 60 projects and by which the tube is lifted it will fold on the intermediate aan shaft is typical merely of a shaftpro-- vided with one or more spiral grooves forming suitable threads yfor co-operation with the nut 26. In this form of my device instead of lthe shaft bein held stationary I allow it to rotate an I hold the other memberA stationary.,` For .this purpose I provide a third bracket 68 which has a bearing 69 in which I rotatably mountV one' end of the s nare tube 641by means of the head 65 whic I project beyond the end of the tube, providing it with a-cylindrical part to fit within the bearing. On the outer end of the head 65 I secure a ratchet d`evice -70 similar to the one already described and held locked against rotation 'by a in 71 which projects through a hole provided in an arm 72 on the bracket 68. I provide a suitable shaft and tube interengaging membervsuch as one of the square nuts 26 fitting within the square tube 64 and 4fitting the threaded part of the shaft and I provide one of the compression springs 37 arranged between the `nut and one of the abutments 35 fixed on Athe shaft as in the former instance, so that as the shaft is rotated to lift the door the spring is permitted to extend and is' compressed as the door is lowered. This compression of the spring' increases its counterbalancin for'ce but the force necessary to counterba ance the door is substantially constant though it may, of course, vary slightly. 0 compensate for the varying power of the spring I provide coned pulleys 73 on the shaft 60 connected by cables 74 to the lower edge of the door.;

the upper ends of the cables are fastened .to the large ends of the pulleys 'and the diameter of the coned pulleys, also that if the force for lifting'the door varies from one extreme to the other, that this "variation can readily be allowed for in the taper of the ulleys and the strength of the spring, so t lat practically, the door will be exactly counterbalanced in all positions.

v It should be understood that while I have illustrated a square nut for engagement with the shaft, and a square tube in which the nut slides, these parts may be varied within the scopel of the appended claims without departing from the spirit of my invention.

I therefore contemplate .forming the engagement between the shaft, nut and tube, in many ways. l

The preferred form is shown in Figures 9 and 10. The round shaft 80 has one or more spiral grooves 81 milled therein. These grooves may be round or square bottomed or of any desired form. An annular collar 82 is provided with one or more internal'spiral ribs 83 for engaging the grooves 81. The number of spiral grooves 81 in the shaft 80 may be varied and may comprise one or more. The annular collar 82 1s preferably formed of phosphor bronze, or alike metal,

tain or shutter,-I employ one or more angle irons 86, which are securely bolted to the inner periphery of the tubularl casing 11.

The inwardly lextending flanges 87 of the i angle irons 86 extend longitudinally through the 'drum 11 and engage in suitable grooves.

88, which grooves 88 are formed in the longitudinal ribs 89, which extendI outwardly from the periphery of the dog 85. The

'grooves'88 are of suicient width that the flanges 87l will be loosely embraced, whereby the dog 85 and collar 82 can-freely slide within thecasing 11 and at the same time rotation of the dog 85 will be effectively prevented. This drum is preferably packed with grease, and as the drum is closed by suitable heads, lubrication is assured.

As hereinbefore pointed out, the dog 85 and the collar 82 mayl be formed of a single piece of phosphor bronze or a like metal, wherein the resistance towear is very great if so desired; such a construction is shown at 90 in Figure 10. It" will also be apparent that the longitudinal ribs 89 which extend outwardly from the periphery of the member 90, may engage in suitable channel members 91 secured to the inner periphery of the tubular casing 11 and extendin longitudinally therethrough( l In either orm there.l are suitable interengaging parts which permit longitudinal movement without permitting rotation.

The drum 11 is provided with suitable heads 15 and 16 shown in Figure 12, and it forms the supporting cylinder for the flexible shutter 1 l As I am aware that many modifications of my invention will readily su gest themselves yto one skilled in the art, I o not intend to limit or confine tmy invention to the specific imacat embodiments herein ,shown and described, although in the variousv forms shown the prominent and important aspect of my invention is theutilization ofthe expansive force of a coiled compression spring as a counterbalancing force.

I claim:

l. ln combination, a vertically movable member varying in weight throughout its various vertical positions, a spring having a varying expansive stress opposing the varying weight of said vertically movable member throughout its vertical movement, the varying expansive stress of said spring counterbalancing said vertically movable member throughout its vertical movement.

2. in combination a vertically movable member, a counterbalance comprising a drum and a screw shaft having relative rotatable movement, an 'abutment having-rectilinear movement along said screw shaft, a relatively stationary abutment, a spring interposed between said relatively movable and stationary abutments, said spring being compressed upon descent of said vertically movable member whereby an increasing rectilinear force is set up to properly counterbalance the increaslng weight of said member.

3. in combination a vertically movable member, a counterbalance comprising a drum and a screw shaft having relative rotatable movement, an abutment having rectilinear movement along said screw shaft,'a relatively stationary abutment, a spring interposed between said relatively stationary and movable abutments, said spring expanding upon ascent of said .vertically movable member whereby a decreasing rectilinear force is set up to properly counterbal'ance the decreasing weight of said member throughout its various vertical positions.

4. in combination a vertically movable member, a counterbalance comprising a drum and a screw shaft having relative rotatable movement, an abutment having rectilinear movement along said screw shaft, a relatively stationary abutment, a spring interposed between said relatively stationary and movable abutments, the compression of said spring upon descent of said vertically movable member and expansion of the spring upon ascent of said vertically -movable member setting up a counterbalancing force varying witlnthe varying weight of said member to properly counterbalance the same throughout its various vertical positions.

5. ln combination a lvertically movable member, a counterbalance comprising a drum and a screw shaft having relative rotatable movement, an abutment having rectilinear movement along said screw shaft, a relatively stationary abutment, a spring interposed between said relatively stationary and movable abutments, said springbeing compressed upon descent of the said vertically movable member whereby a force is set up in opposition to the relative rotative movement between said drum and said shaft, the` force set up by said spring increasing with the increasing weight of said member to properly counterbalance the same throughout its various positions.

6. In combination a vertically: movable member, a counterbalance comprising a sleeve member and a shaft having relative rotatable movement, an abutment having rectilinear movement along said shaft, a second abutment fixed relative said first abutment, a spring member freelyinterposed between said abutments and adapted to be compressed therebetween upon descent ofthe vertically movable member, setting upa recinto rectilinear movement of said second abutment whereupon said spring is contracted or expanded without twisting or winding the same.

8. in combination, a rotatable drum., a relatively fixed abutment therein, a second abutment interlocked for rotation with said lrotatable drum, said abutment having rectilinear movement within said drum, means for converting rotation of said drum into rectilinear movement of said second abutment and va coiled spring interposed between and having its opposite ends freely engaging said relatively fixed and rela-tively movable abutments respectively.

9. ln a counterbalance, a sleeve member and a shaft having relative rotation, an abutment interlocked for rotation with the rotatable member, said abutment having rectilinear movement along said shaft, a spring interposedpbetween and having its opposite ends freely engaging said movable and stationary abutments respectively, said spring member being compressed by relative movement between said abutments upon application of a varying force to be counterbalanced, whereupon a varying counterbalancing force is set up in said spring in opposition to said first force,

l0. in combination, a winding drum for shutter doors, arrelatively stationary abutment, a springdisposed within said winding drum, one end of said spring freely engaging said relatively stationary abutment, an abutment arranged for rotation with said drum, said abutment compressing said spring without twisting or otherwise subjecting the same thereof.

12. In combination, awinding drum, a

relatively stationary shaft carrying said drum, head members closing off the ends of said drum, a relatively fixed abutment on said` shaft, an abutment interlooked for rotation with said drum, said abutment having axial movement along said shaft and a spring member interposed between said relatively stationary and axially movable abut- Yment, said drum forming a lubricant chamber. Y

In Witness whereof I hereunto subscribe my name this 1st day of February, 1919.

SAMUEL P. SMURR. 

